Chromosome 3, Monosomy 3p
Chromosome 3, Monosomy 3p
National Organization for Rare Disorders, Inc.
It is possible that the main title of the report Chromosome 3, Monosomy 3p is not the name you expected. Please check the synonyms listing to find the alternate name(s) and disorder subdivision(s) covered by this report.
Related Disorders List
Information on the following diseases can be found in the Related Disorders section of this report:
- Chromosomal Disorders
Chromosome 3, Monosomy 3p is a rare chromosomal disorder in which the end (distal) portion of the short arm (p) of chromosome 3 is missing (deleted or monosomic). The range and severity of symptoms and findings may be variable. However, associated features often include growth delays before and after birth (prenatal and postnatal growth deficiency); severe to profound mental retardation; distinctive malformations of the skull and facial (craniofacial) region; eyebrows that grow together (synophrys); and/or excessive hair growth (hypertrichosis). Additional physical abnormalities may also be present. In many cases, Chromosome 3, Monosomy 3p appears to occur spontaneously (de novo) for unknown reasons.
As noted above, the symptoms and physical findings associated with Chromosome 3, Monosomy 3p may vary in range and severity from case to case. However, according to reports in the medical literature, many affected individuals have a low birthweight; marked growth delays after birth (postnatal growth retardation); severe to profound mental retardation; severe delays in the acquisition of skills requiring the coordination of mental and motor activities (psychomotor retardation); excessive hair growth (hypertrichosis); and/or distinctive malformations of the skull and facial (craniofacial) region.
Many affected infants have an abnormally small head (microcephaly) that may appear unusually short and broad (brachycephaly); a flat back region of the head (occiput); and/or an abnormally high, narrow, prominent forehead. Additional craniofacial abnormalities may include a triangular face; arched eyebrows that grow together (synophrys); a broad, flat nose; an unusually long vertical groove in the middle of the upper lip (philtrum); thin lips; and/or an abnormally small lower jaw (mandible). Affected individuals may also have a downwardly turned mouth; widely spaced eyes (ocular hypertelorism); vertical skin folds that cover the eyes' inner corners (epicanthal folds); upwardly slanting eyelid folds (palpebral fissures); drooping of the upper eyelids (ptosis); and/or low-set, malformed ears.
Chromosome 3, Monosomy 3p is also commonly associated with more than the normal number of fingers and/or toes (polydactyly). In many cases, there may be additional fingers, particularly duplication of the "pinkies" or fifth fingers (postaxial polydactyly). In addition, in some instances, affected infants may have duplication of certain toes, particularly the fifth toes.
Reports indicate that some affected individuals may also have hearing loss and/or visual impairment. In addition, the disorder may be associated with additional physical features, such as abnormal forward (anterior) placement of the anus; undescended testes (cryptorchidism) in affected males; kidney (renal) defects: structural malformations of the heart (congenital heart defects); and/or other abnormalities.
Chromosome 3, Monosomy 3p is a rare chromosomal disorder in which there is deletion (monosomy) of the end (distal) portion of the short arm (p) of chromosome 3. Researchers indicate that symptoms and findings characteristic of the syndrome result from deletion of chromosomal material extending from band 25 on the short arm of chromosome 3 (breakpoint) to the end or "terminal" of 3p (3p25-->pter). Chromosomes are found in the nucleus of all body cells. They carry the genetic characteristics of each individual. Pairs of human chromosomes are numbered from 1 through 22, with an unequal 23rd pair of X and Y chromosomes for males and two X chromosomes for females. Each chromosome has a short arm designated as "p" and a long arm identified by the letter "q". Chromosomes are further subdivided into bands that are numbered. Therefore, 3p25 refers to band 25 on the short arm of chromosome 3.
In most reported cases, Chromosome 3, Monosomy 3p has appeared to result from spontaneous (de novo) errors very early in embryonic development. In such instances, the parents of the affected child usually have normal chromosomes and a relatively low risk of having another child with the chromosomal abnormality.
All cases of Monosomy 3p except for one have been new chromosomal changes (de novo). In one case, the deletion was inherited from the mother who had the same deletion 3p. Potentially, monosomy 3p could result from a parental translocation or inversion.
Translocations occur when regions of certain chromosomes break off and are interchanged, resulting in shifting of genetic material and an altered set of chromosomes. If such chromosomal rearrangements are "balanced", all of the chromosomal material is present in two copies but at different locations. Balanced translocations are usually harmless to the carrier. However, such chromosomal rearrangements may be associated with an increased risk of abnormal chromosomal development in the carrier's offspring if inherited in an "unbalanced" state. An unbalanced translocation occurs when only one of the two chromosomes involved in the translocation is inherited from a carrier parent. The result is too much (duplication or trisomy) or too little (deletion or monosomy) chromosomal material. An inversion occurs when a chromosome breaks in two places within a single chromosome and the segment between the breaks rejoins the chromosome in the reverse order. Chromosomal analysis and genetic counseling are typically recommended for parents of an affected child to help confirm or exclude a chromosomal rearrangement in one of the parents.
Chromosome 3, Monosomy 3p appears to affect males and females in relatively equal numbers. Since the disorder was originally reported in 1978 (Verjaal M), approximately 34 cases have been described in the medical literature.
Additional chromosomal disorders may have features similar to those associated with Chromosome 3, Monosomy 3p. Chromosomal analysis is necessary to confirm the specific chromosomal abnormality present. (For further information on such disorders, choose the name of the specific chromosomal disorder in question or use "chromosome" as your search term in the Rare Disease Database.)
In some cases, Chromosome 3, Monosomy 3p may be suggested before birth (prenatally) by specialized tests such as ultrasound, amniocentesis, and/or chorionic villus sampling (CVS). During fetal ultrasonography, reflected sound waves create an image of the developing fetus, potentially revealing certain findings that suggest a chromosomal disorder or other developmental abnormalities in the fetus. With amniocentesis, a sample of fluid that surrounds the developing fetus is removed and analyzed, while CVS involves the removal of tissue samples from a portion of the placenta. Chromosomal analysis performed on such fluid or tissue samples may reveal the presence of Monosomy 3p.
The disorder may also be diagnosed or confirmed after birth (postnatally) based upon a thorough clinical evaluation, detection of characteristic findings (e.g., growth delays, mental retardation, psychomotor retardation, craniofacial abnormalities, etc.), and chromosomal analysis. Specialized tests may also be conducted to help detect and/or characterize certain abnormalities that may be associated with the disorder.
The treatment of Chromosome 3, Monosomy 3p is directed toward the specific symptoms that are apparent in each individual. Such treatment may require the coordinated efforts of a team of medical professionals, such as pediatricians; surgeons; neurologists; physicians who diagnose and treat heart abnormalities (cardiologists); hearing specialists; and/or other health care professionals. In some cases, physicians may recommend surgical repair of certain malformations associated with the disorder. The specific surgical procedures performed will depend upon the severity and location of the anatomical abnormalities, their associated symptoms, and other factors.
Early intervention may be important in ensuring that affected children reach their potential. Special services that may be beneficial include special education, physical therapy, and/or other medical, social, and/or vocational services. Genetic counseling will also be of benefit for families of affected children. Other treatment for this disorder is symptomatic and supportive.
Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. government funding, and some supported by private industry, are posted on this government web site.
For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:
Tollfree: (800) 411-1222
TTY: (866) 411-1010
For information about clinical trials sponsored by private sources, contact:
Jones KL. Smith's Recognizable Patterns of Human Malformation. 5th ed. Philadelphia, PA; W.B. Saunders Company; 1997:34-35.
Buyse ML. Birth Defects Encyclopedia. Dover, MA; Blackwell Scientific Publications, Inc.; 1990:332.
Gorlin RJ, et al., eds. Syndromes of the Head and Neck. 3rd ed. New York, NY; Oxford University Press; 1990:72.
Kariya S, et al. A terminal deletion of the short arm of chromosome 3: karyotype 46, XY, del (3) (p25-pter); a case report and literature review. Int J Pediatr Otorhinolaryngol. 2000;56:71-78.
Angeloni D, et al. CALL gene is haploinsufficient in a 3p- syndrome patient. Am J Med Genet. 1999;86:482-85.
Benini D, et al. 46, XY, del (3) (pter-->p25) syndrome: further delineation of the clinical phenotype. Eur J Pediatr. 1999;158:955-57.
Lukusa T, et al. A 3p deletion syndrome in a child with both del(3)(p25-->pter) and dup(17)(q23-->qter). Ann Genet. 1999;42:91-94.
Narahara K, et al. Loss of the 3p25.3 band is critical in the manifestation of del(3p) syndrome: karyotype-phenotype correlation in cases with deficiency of the distal portion of the short arm of chromosome 3. Am J Med Genet. 1990;35:269-73.
Schwyzer U, et al. Terminal deletion of the short arm of chromosome 3, del(3pter-p25): a recognizable syndrome. Helv Paediatr Acta. 1987;42:309-15.
Tolmie JL, et al. Partial deletion of the short arm of chromosome 3 [letter]. Clin Genet. 1986;29:538-40.
Higginbottom MC, et al. A second patient with partial deletion of the short arm of chromosome 3: karyotype 46,XY,del(3)(p25). J Med Genet. 1982;19:71-73.
Verjaal M, et al. A patient with a partial deletion of the short arm of chromosome 3. Am J Dis Child. 1978;132:43-45.
Children's Craniofacial Association
13140 Coit Road
Dallas, TX 75240
March of Dimes Birth Defects Foundation
1275 Mamaroneck Avenue
White Plains, NY 10605
1825 K Street NW, Suite 1200
Washington, DC 20006
PO Box 751112
Las Vegas, NV 89136
Chromosome Disorder Outreach, Inc.
P.O. Box 724
Boca Raton, FL 33429-0724
American Heart Association
7272 Greenville Avenue
Dallas, TX 75231
NIH/National Eye Institute
31 Center Dr
Bethesda, MD 20892-2510
NIH/National Kidney and Urologic Diseases Information Clearinghouse
3 Information Way
Bethesda, MD 20892-3580
NIH/National Institute on Deafness and Other Communication Disorders
31 Center Drive, MSC 2320
Bethesda, MD 20892-3456
UNIQUE - Rare Chromosome Disorder Support Group
The Rare Chromosome Disorder Support Group
G1 The Stables
Station Road West, Oxted
Surrey, RH8 9EE
Email: firstname.lastname@example.org or email@example.com
Craniofacial Foundation of America
975 East Third Street
Chattanooga, TN 37403
Genetic and Rare Diseases (GARD) Information Center
PO Box 8126
Gaithersburg, MD 20898-8126
For a Complete Report
This is an abstract of a report from the National Organization for Rare Disorders, Inc.® (NORD). Cigna members can access the complete report by logging into myCigna.com. For non-Cigna members, a copy of the complete report can be obtained for a small fee by visiting the NORD website. The complete report contains additional information including symptoms, causes, affected population, related disorders, standard and investigational treatments (if available), and references from medical literature. For a full-text version of this topic, see http://www.rarediseases.org/search/rdblist.html.
The information provided in this report is not intended for diagnostic purposes. It is provided for informational purposes only. NORD recommends that affected individuals seek the advice or counsel of their own personal physicians.
It is possible that the title of this topic is not the name you selected. Please check the Synonyms listing to find the alternate name(s) and Disorder Subdivision(s) covered by this report
This disease entry is based upon medical information available through the date at the end of the topic. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder.
For additional information and assistance about rare disorders, please contact the National Organization for Rare Disorders at P.O. Box 1968, Danbury, CT 06813-1968; phone (203) 744-0100; web site www.rarediseases.org or email firstname.lastname@example.org
Last Updated: 4/10/2009
Copyright 1994, 2001, 2003, 2009 National Organization for Rare Disorders, Inc.
Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.